Positive accel.=increase in speed
negative accel.= decrease in speed
Answer: initially the packet was ascending up with the balloon.
Taking upward as positive direction;
initial velocity, u = 4.9 m/s
final velocity = v m/s
initial height, h₁ = 245 m
final height, h₂ = 0
a = -9.8 m/s²
time taken = t seconds
s = ut + 0.5at²
⇒ (h₂-h₁) = ut + 0.5at²
⇒ 0-245 = 4.9t + 0.5×(-9.8)×t²
⇒ -245 = 4.9t - 4.9t²
⇒ 4.9t² -4.9t -245 =0
Solving it, we get t = 7.59s
v = u + at = 4.9 -9.8×7.59 = 4.9 - 74.38 = -69.48 m/s
So velocity is 69.48 m/s downward
Explanation:
Answer:
The speed of the stone before it hit the river 3.00 sec later. Let v is the velocity at that instant is 45 m/s.
Explanation:
Given that, a child threw a stone straight down off a high bridge.
Initial velocity of the stone, u = 15 m/s
We need to find the speed of the stone before it hit the river 3.00 sec later. Let v is the velocity at that instant. When it come down, it is moving under the action of gravity. Using equation of motion as :
![v=u+gt\\\\v=15+10\times 3\\\\v=45\ m/s](https://tex.z-dn.net/?f=v%3Du%2Bgt%5C%5C%5C%5Cv%3D15%2B10%5Ctimes%203%5C%5C%5C%5Cv%3D45%5C%20m%2Fs)
So, the speed of the stone before it hit the river 3.00 sec later. Let v is the velocity at that instant is 45 m/s.
Detailed Explanation:
1) Rusting of Iron
4Fe + 3O2 + 2H2O -> 2Fe2O32H2O
Reactants :-
Fe = 4
O = 3 * 2 + 2 = 8
H = 2 * 2 = 4
Products :-
Fe = 2 * 2 = 4
O = 2 * 3 + 2 = 8
H = 2 * 2 = 4
2) Fermentation of sucrose…
C12H22O11 + H2O -> 4C2H5OH + 4CO2
Reactants :-
C = 12
H = 22 + 2 = 24
O = 11 + 1 = 12
Products :-
C = 4 * 2 + 4 = 12
H = 4 * 5 + 4 = 24
O = 4 * 2 + 4 = 12
Looking closely at the way I have taken the total number of elements on the reactants and products side, you can solve the rest.
All the Best!
Answer:
C
Explanation:
Force is a vector quantity. So, it has magnitude and direction which can also be describe as strength and direction